Typewriter ribbon



Patented June 5, 1934 1,962,082 TYPEWRITER RIBBON Samuel Eugene Miller,

Aurora, 111., assignor to L. C. Smith & Corona Typewriters, Inc., Syracuse, N. Y., a corporation of New Jersey No Drawing. Application March 25, 1932, Serial No. 601,109

10 Claims.

for contact with the paper, and co-acts with the ink coating for the body of the ribbon in the transfer of the type impression.

In the manufacture of typewriter ribbons, it is customary to coat or impregnate the fabric of the ribbon with ink ofa character fully understood in the art, and to inscribe the type impression by the direct contact of the inked fabric under the impact of the type. Such an operation tends to lack 'of uniformity in the appearance of the type impressions, due to va-- riations in the strength of impact of the type, and to smear the ink and to lack of sharpness or clearness in definition of the writing.

The present invention consists essentially in the provision of a'surface ink coating, which is applied directly to the surface of the ribbon in advance of the application of the ribbon ink for the purpose ,of initiating a sharper type impression than it is possible to secure directly from the ribbon ink and which sharp initial impression is strengthened and reinforced by the ribbonink.

The ink surface coating of the present invention is of a harder or firmer consistency than that afforded by the ribbon ink, which impregnatescthe body of the ribbon, with the result that the type impact has the effect of first forming a relatively light or delicate and clear-cut impression created by the contact of the coating ink, and thereafter intensifying and deepening said initial impression.

In carrying .out the details of the' present invention, I find that by first coating a ribbon with the surface ink coating of carbon paper ink and afterwards impregnating the ribbon on the reverse side with ribbon ink of standard quality, and of the character now commonly employed in the making of typewriter ribbons, thata ribbon possessing the characteristics of the present invention will be produced.

The carbon paper ink is preferably of a firm consistency by reason of the inclusion of an adequate amount of hard wax gums or other hardening [ingredient with the pigments and oils commonly employed in the making of carbon paper coatings. The inclusion of the wax or other hardener gives a firm glossy surface to the ink coating, and prevents its ready transfor to the paper, save under the impact-of the type, and the firm-texture of the coating serves to prevent spreading or smearing of the ribbon ink which reinforces the lines formed by the carbon ink coating.

It will also be understood that the present invention is not directed to any particular formula of ingredients employed in the ribbon ink and/or the surface coating, since the ribbon ink may be of any standard quality commonly employed in the making of typewriter ribbons, and the surface coating may be of any 5 character commonly employed in the making of carbon sheets, it being understood, however, that a relatively firm textured surface coating is preferred for the purposes of the present in-. vention.

If it is desired to positively retard the transfer and discharge of the ribbon ink, the ribbon first described may be additionally treated to a thin coating of cellulose on one of its surfaces before the application of the supplemental carbon ink coating, so that the cellulose coating will act as a screen or filter through which the ribbon ink must be-driven before it can be expelled through the supplemental ink coating.

The ribbon treated in the manner last referred to will have the cellulose surface coating applied to the fabric of the ribbon in the form of a thin surface layer, which is'pervious to the passage of ribbon ink under pressure, and upon the surface of the cellulose coating the supplemental carbon ink coating will be applied and constitutes the writing surface of the ribbon. In short the cellulose coating will be interposed between the fabric impregnated with the ribbon ink and the surface coating of carbon ink with the result that the transfer of. the ribbon ink will be somewhat retarded and the supply of ribbon ink conserved.

The cellulose coating must be thinly applied in order not to render the surface of the fabric completely impervious to the penetration of the ribbon ink under the impact of the type.

The following constitutes a satisfactory formula for the cellulose coating: A mixture of pyroxylin solution and an equal amount of pyroxylin cement. The pyroxylin solution contains four parts of pyroxylin to five parts ,of a softener, such as castor oil, to which is added a low boiling, point solvent, such as ethyl acetate diluted with a quick drying liquid such as gasoline, alcohol or acetone. Pyroxylin cement is the same as pyroxylin with the softener omitted and gums or resins added, which seem to give greater flexibility and adhesion.

The cellulose may be applied as a single coating applied to the fabric of the ribbon for the purpose of retarding the transmission of the ribbon ink to the surface contiguous to the paperbeing typed, it will be understood that the use of the cellulose coating is optional and desirable only in cases where conservation of the ribbon ink is required.

The present invention is one which affords a firm glossy s urface contiguous to the paper sheets, so that the danger of smearing or accidently marking the sheets by contact with the ribbon is reduced to a minimum, and at the same time the clearness of the type impressions is enhanced.

I claim:

1. A typewriter ribbon comprising a fabric impregnated with ribbon ink and having a coating ink surface of relatively harder consistency to give sharp type impressions to be reinforced by the ribbon ink therethrough.

2. A typewriter ribbon having its fabric impregnated with ribbon ink and having a surface coating composed of ink of wax-like consistency, and adapted to give sharp type impressions to be reinforced by the ribbon ink.

3. A typewriter ribbon having its body fabric impregnated with ribbon ink and having a coating of carbon paper ink applied thereto.

4. A typewriter ribbon having its fabric impregnated with ribbon ink and having a surface coating of relatively firm carbon paper ink applied thereto.

5. A typewriter ribbon having its fabric inipregnated with ink and having a surface coating of ink of a different consistency than the ink first mentioned.

6. A typewriter ribbon having its fabric impregnated with ink and having a coating of pervious material applied thereto to constitute a screen and having a surface coating of ink applied to the said screen coating.

'7. A typewriter ribbon having its fabric impregnated with ink and having a coating of pervious material applied thereto to constitute a screen and having a surface coating of ink applied to the said screen coating,-the surface coating being of a firmer texture than the ink impregnating the fabric of the ribbon.

8. A typewriter ribbon having its fabric impregnated with ribbon ink and having a pervious coating applied thereto to form a screen for retarding the transmission of ribbon ink and the screen coating having a surface coating of ink of a different consistency applied thereto.

9. A typewriter ribbon having its fabric impregnated with ribbon ink and having a pervious coating applied thereto to constitute a screen for the passage of the ribbon ink and a surface coating for the screen consisting of carbon paper ink.

10. A typewriter ribbon having its fabric impregnated with ribbon ink and having a pervious coating applied thereto to constitute a screen for the passage of the ribbon ink and a surface coating for the screen consisting of carbon paper ink of relatively firm smooth surface texture.

s. EUGENE MILLER. 

